All experienced diamond graders understand that clarity grades can differ because of any number of inclusion characteristics. Such differences may, for example, include differences in an inclusion's size, type, position or relief (i.e., brightness). However, graders generally cannot describe exactly how much each characteristic actually influences the ultimate clarity grade. Instead, graders mostly rely on their diamond grading training and experience to provide them with a memory of visual references with which to evaluate each new case individually. For example, to ascertain how a SI1 inclusion located near the girdle would be graded if it were located in the center of the table, or how a VS2 inclusion with a Low relief would be graded if it had a High relief instead, is nearly impossible for a grader to do without concrete examples to refer to. In many situations, extensive reliance on concrete examples, however, is impractical since it would be difficult, expensive, and impracticable to obtain concrete examples of every possible inclusion characteristic combination. Consequently, the clarity grading process is vulnerable to the grader subjectivities, which can affect the consistency of clarity grades in the field.
In view of the need for consistency and uniformity in the clarity grading process, developing tools that could more objectively, and preferably mathematically, predict the influences of particular inclusion characteristics on clarity grade would be extremely helpful. Such tools, may then be used to better understand the visual clarity grading decision processes, and to help provide consistency in these processes by providing these tools to grader trainees uniformly. Accordingly, there is currently a need for an improved method and system for providing a clarity grade for a gem.